Monoazo dyes



United States PatenttCf y 2,776,960 'Patenied Jan. 8, 1957 ice `1Fra'z Frisch, Arlesheim, Switzerland; :assigner to Sandoz Y'A.\G.,\=Basel, SwitzerlandyaSwi'ss firm '"N-oflmiwmg.N -piilicitiaqneeemberzsy1952,

Sll NOISZISSl-'l l Claims priority, application Switzerland January 9, 1952 7 Claims. (Cl. 2611-196) The present invention relates to monoazo dyes, and is based on the observation that thesclass of monoazo` dyes corresponding to the formula whereinhe "residue hydrogen or lower alkyl, R3 stands@foiilweralkylrcyloalkyl, aralkyl or phenyl, 4R1 stands for hydrogen, methyl or ethyl, x stands for Iwfalkyl, cycloalkyl, aralkyl,

radicalsof thebenzeneseries or thearesidue l "aprima'ry `or'secoiidary-aminewhich'contains a maximum the nitrogen ratom, rvand lR stands "for a"radic`al of the benzene series which 'containsa nuclearlyfbourid carboxyl `group `and "the ortho-position "of "which is occupied by IhydroxyL with an fiainirforiphthal'ene" compound *of the formula red dyestuff precipitates.

plction of the coupling, the dyestut is separated by filtratron, 1f necessary after evaporating oi the organic solvent, and is then converted into the ammonium, lithium,

y sodium or potassium salt by dissolving it in dilute aque- The following examples are illustrative, but not limita-- tive, of the invention. In the said examples, the parts are parts by weight, the percentages are by weight, and the temperatures are set forth in degrees centigrade.

Example 1 37.1 parts of 2-amino-4-methylsulfone-4'hydroxy-1,1-

diphenylsulfone-3'-carboxylic acid are dissolved in S00 v parts of water with the aid of sodium hydroxide, 36 parts of a 20% aqueous sodium nitrite solution are added to the resultant solution, after which the mixture is run in the course of a half hour into a mixture of 40 parts of concentrated hydrochloric acid and 200 parts of Water at a temperature of at most 10. The resultant yellowish diazo compound is substantially completely precipitated. Upon completion of the diazotization, excess nitrous acid is destroyed, and to the diazo suspension, acid to Congo red, there is added dropwise at 10-15 and in the coursev of a half hour a solution of 34.2 parts of 2amino8hy tlroxynaphthalene 6 sulfonic acid-N-ethyl-phenylamide in 200 parts of methyl alcohol. Coupling takes place in the hydrochloric acid suspension, and the produced bluepling, the dyestul is ltered oi and washed with water. ln order to convert it into `the readily soluble sodium salt, it is dissolved in warm aqueous sodium carbonate solution, if necessary impurities are filtered off, the product salted out with sodium chloride, the precipitate filtered off and dried. The dyestuf is a blue-red powder which corresponds to the formula ooon l: NH:

(132115 sor-CH3 soz-N@ 37.1 parts of Z-amino-4-methylsulfone-4'-hydroxy-1,1'-

' diphenylsulfone-3'-carboxylic acid are diazotized as de- The dyeings are Upon completion of the cou-` scribed in Example l. Into the diazo suspension, a solution of 25 parts of 2-methylaminonaphthalene-G-sulfonic acid-methylamide in 200 parts of water and 15 parts of concentrated hydrochloric acid is run at 10 in the course of 10 minutes. Coupling starts immediately and the produced red dyestui precipitates. After stirring for one hour, the coupling mass is made neutral to Congo red by the dropwise addition of a concentrated aqueous sodium acetate solution. The dyestul is iiltered oi and is converted with aqueous ammonia into the ammonium salt and worked up, after the manner described in Example l for the preparation of the sodium salt. The dyestuit` is a red powder which corresponds to the formula BIO: NH--CHa SOz--CH-x SOr-NH--OHs dissolves readily in hot water with resultant red coloration, and dyes wool from a neutral or weakly acid bath in vivid red shades which undergo but slight change upon being afterchromed. The dyestuff is also suitable for dyeing according to the single bath chrorning process. The dyeings possess very good fastness to light, fulling and carbonization. l

A similar dyestuft with even better neutral exhausting capacity is obtained when, in the preceding paragraph, 44.7 parts of 2amino-4-benzylsulfone-4'-hydroxy-l,l'- diphenylsulfone-3'-carboxylic acid are used to prepare the diazo compound.

Example 3 44.8 parts of 2-amin0-4-sulfonic acid-phenylamide-l'- hydroxy-1,1'-diphenylsulfone-3'-carboxylic acid are diazotized after the manner described in Example l. A solution of 25 parts of Z-methylaminonaphthalene-6sul fonic acid-methylamide in 200 parts of water and 1S parts of concentrated hydrochloric acid is run into the diazo suspension at 10 in the course of l0 minutes. Coupling commences forthwith and the produced red dyestul separates out. After stirring for an hour, the coupling mass is adjusted to neutrality toward Congo red by the dropwise addition of a concentrated aqueous sodium acetate solution. The dyestuff is ltered off and is converted with lithium carbonate into the lithium salt and worked up,` after the manner described for the preparation of the sodium salt in Example 1. The dyestu is a red powder which corresponds to the formula BOr-JNH--CHI Ox-N'H dissolves.. readily in het water,Y and` dyes wool fram a neutral or weakly acid. bath. in vividred shades; which change only slightly upon being afterchromed. Thefdye.- stuff is excellently suited for dyeing according to the single bath chroming process. The dyeings possess very good fastness to light, fullingand carbonization.

A similar dyestui is, obtained when, in the preceding paragraph, the coupling is carried out with 32 parts of 2- methylaminonaphthalene 64 sulfonic. acid-.cyclohexyl amide..

Example 4 37.1 parts of 2-amino4-methylsulfone-4'hydroxy1,1'- diphenylsulfone-3'-carboxylic acid.: are diazotized. Into the diazo suspension, rendered acid wither-.mineral acid, there is added dropwise at in the course of a half hour a solution of 31.2 parts of Z-methylaminonaphthalene--sulfonic acid-phenylamide in 2 0() parts of methyl alcohol. Coupling takes` place forthwith, and resultant dyestut is partly precipitated; After stirring for one hour, the suspension is adjusted to neutrality to Congo red with the aid of aqueous sodium acetate solution, and the methyl alcohol is evaporated. The produced dyestuff is filtered olf cold and is converted into the potassium salt withthe aid of potassium carbonate and worked up, after the, manner described in Example l for the preparation ot the sodium salt. The dyestutie a red powder which corresponds to` the.. formula1 ITE-C Ha SO2-CH2 dissolves readily in hot water, and dyes wtool from a neutral or weakly acid bath in vivid redt shades, whichl A similar dyestul, which, is bluish red, is obtained f when, in the preceding paragraph, the coupling is carried out with 31.2 parts of 2-methylaminonaphthalene-7- sul fonic acid-phenylamide.

Example 5 37.1 parts of 2-amino-4-methylsulfone-4'hydroxy l,1'-diphenylsulfone-3'-carboxylic acidi are diazotized, after the manner described in Exampley 1. A solution of 29.8 parts of 2aminonaphthalene--sulfonic acidphenylamide in 300 parts of methyl alcohol is added dropwise to the diazo suspension, rendered acid with a mineral acid, at 10 to 15 in the courseof one hour. Coupling begins at once, and the produced dyestui separates out. After stirringfor 2 hours, the suspension is rendered neutral to Congo red'-y with the aid of an aqueous sodium acetate solution, after which the dyestuff is ltered off and converted with ammonia into the ammonium salt and Worked up, after the manner described in Example 1f for the preparation of the sodium i amino-4-sulfonic 1" SO2-CH3 dissolves readily` in hot. Water andv dyes.4 wool from a neutral or weaklyy acid bath. invividf orange shades, which undergor but Slight change upony afterchroming.. The dye-Studis excellently suitedfor dyeingaccordingto-the single bath chroming process. The dyeingsI are of very good fastness to fulling and to carbonization and areI of excellent fastness to light.

Dyestutfs with similar properties are obtained when, in this example, on the one hand, the 2,-,.'amino-4-rnethylsulfone4hydroXyl-,l'-diphenylsulfone-3'-/carboxylic acid, used to prepare the diazo compound, is replaced by an equivalent quantity of one of the following carboxylic acids: 2-amino-4-ethylsulfone4hydroxy1, 1 diphenylsu1fone-3'carboxylic acid, 2-amino-4-n-propylsulfone-4' hydroxy-1,1-dipheny1sulfone3'-carboxylic acid, 2amino 4-cyclohexylsulfone-4'hydroxy1,1 diphenylsulfone 3'- Example 6 parts of pre-wetted: Woolv are entered at 30-40 into a dyebath consisting of 2 parts of the dye disclosed" in Example 11, paragraph l, lpartr of potassium chromate, 5 parts of ammonium sulfate, l0 parts of sodium sulfate and 5000 parts of Water. The temperature is raised" to 100, while stirring frequently, and the bath is maintained at boiling temperature for one and one-half hours. At the end of this period of time, the dyestul will have completely drawn onto the wool; thereupon the dyed material is thoroughly rinsed with Coldwater and dried. An eX- Icellent dyeing is obtained.

The 2 parts of the dyestuft mentioned in the preceding paragraph may, with similar results, be replaced by 2 parts of any other one of the dyes disclosed in the foregoing Examples 1 to 5.

Example 7 100 parts of wool are entered into a dyebath consisting of 2 parts of dyestuff, 2 parts of concentrated acetic acid, 10 parts of sodium sulfate and 5000 parts of water. The bath is brought to boiling in the course of one-half hour and is then maintained at boiling temperature for 1 hour. During this time, 2 parts of concentrated formic acid are added to the bath. Upon completion of the dyeing process, the bath is cooled to 70 by the addition of cold water, after which l part of potassium biehromate is added and the bath again boiled for one-half hour. At the end of this operation, the dyeing will be Chromed; it is then rinsed and dried. The 2 parts of dyestut may be of any one of those disclosed in the preceding examples.

Having thus disclosed the invention what is claimed is:

1. A monoazo dyestui which corresponds to the formula stands in one of the positions 6 and 7, R2 stands for a member selected from the group consisting of hydrogen and lower alkyl, R3 stands for a member selected from the group consisting of lower alkyl, cycloalkyl, aralkyl and phenyl, R1 stands for a member selected from the group consisting of hydrogen, methyl and ethyl, x stands for a member selected from the group consisting of lower alkyl, cycloalkyl, aralkyl, mononuclear carbocyclic aryl, amino, lower alkylamino, cycloalkylamino, aralkylamino, phenylamino, methylphenylarnino, N,N- lower dialkylamino, N-lower alkyl-Naralkylamino and N-lower alkyl-N-phenylamino, the substituted amino groups containing a total of not more than 14 carbon atoms, y stands for a member selected from the group consisting of hydrogen and methyl, and z stands-when the residue is in position -for a member selected from the group consisting of hydrogen and hydroxy, andwhen the residue is in position 7--for hydrogen.

2. A monoazo dye which corresponds to the formula -oooH so, rIH-Rt BRN@ /R1 sor-z sor-N wherein R1 stands for a member selected from the group consisting of hydrogen, methyl and ethyl, Rz; stands for a member selected from the group consisting of hydrogen and lower alkyl, R3 stands for a member selected from the group consisting of lower alkyl, cycloalkyl, aralkyl and phenyl, x stands for a member selected from the group consisting of lower' alkyl, cycloalkyl, aralkyl, mononuclear carbocyclic aryl, amino, lower alkylarnino, cycloalkylamino, aralkylamino, phenylarnino, methylphenylamino, N,Nlower di-alkylamino, N-lower alkyl- N-aralkylamino and N-lower alkyl-N-phenylamino, the substituted amino groups containing a total of not more than 14 carbon atoms, y stands for a member selected from the group consisting of hydrogen and methyl, and z stands for a member selected from the group consisting of hydrogen and hydroxy.

3. The monoazo dye which corresponds to the formula 0H @ce ou S0 NH2 4. The monoazo dye which corresponds to the formula 0H ooon SOs B01-:CHI ORNE-CH3 5. The monoazo dye which corresponds to the formula 7. The monoazo dye which corresponds to the formula oooH oo 0H SO: NHG-OH: 0a NH:

N=N N:

slm-NH-om sor-0H. sor-NH@ Or-NH 6. The monoazo dye which corresponds to the formula References Cited in the le 0f this Patent OH f UNITED STATES PATENTS 1,901,515 Hentrich et al Mar. 14, 1933 COOH 2,476,259 Mayer et al. July 12, 1949 v o: N11-om sos-JH slof-Nn@ 30 

1. A MONOAZO DYESTUFF WHICH CORRESPOMDS TIO THE FORMULA 